v0.8.3

- Fixed black background of favorite picklist when in light theme
- Fixed favorite list not working correctly anymore (disabled when
adding favorites)
- Fixed removing items from favorite list
- Moved logo up on about page
- Changed margin of mounted text on GameInfo page
- Fixed favorite button not updating anymore on GameInfo page
- Added INamedItem interface to handle differences between Games and
Favlists correctly (InvalidCastException in Wall.xaml.cs when setting
source)
- Made FavLists ObservableCollections